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Objective:To analyze the prevalence of influenza B virus in Hangzhou from 2014 to 2020 and the genetic evolution of seven reassortant strains of influenza B virus.Methods:Influenza viruses were isolated from throat swabs collected from 16 943 patients with influenza-like illness in Hangzhou from January 2014 to December 2020. The subtypes of influenza viruses were identified by real-time RT-PCR. Eight genes ( PB2, PB1, PA, HA, NP, NA, MP and NS) of influenza B viruses were amplified with specific primers and then analyzed with nanopore sequencing and phylogenetic analysis. Results:From January 2014 to December 2020, there were 1 090 influenza B virus-positive samples, including 474 samples of Yamagata lineage and 616 samples of Victoria lineage, were identified in Hangzhou with an overall positive rate of 6.43% (1 090/16 943). Whole genomes of 228 strains of influenza B virus were obtained by nanopore sequencing and seven reassortant strains of influenza B virus were found. There were four reassortant influenza B viruses of Yamagata lineage with NA gene fragments from viruses of Victoria lineage, two strains of Yamagata lineage (H644_BY and H648_BY) with NP and NA gene fragments from Victoria lineage and one strain of Victoria lineage with PB2, PB1, PA and NS gene fragments from Yamagata lineage. Meanwhile, these seven strains possessed several mutations in the antigenic sites of HA and NA genes. Conclusions:Several rare reassortant strains of influenza B virus with epidemic potential were detected in Hangzhou from 2014 to 2020, which indicated that the traditional detection methods should be improved and more attention should be paid to the reassortant influenza B viruses and the match between epidemic and vaccine strains.
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Objective:To study the epidemiological features of local influenza A(H1N1)pdm09 epidemic strains through analyzing the changes in lineages and to analyze how well the vaccine strains were matched to the circulating strains in Hangzhou.Methods:Of 1 112 clinical specimens from laboratory-confirmed A(H1N1)pdm09 infections in Hangzhou in consecutive seasons from 2009 to 2020, 208 (18.7%) with high viral load (Ct value <30) were randomly selected from 10 influenza epidemics for full-length hemagglutinin gene ( HA) gene sequencing. Genetic variation, evolution and lineage changes of these representative local strains were analyzed by comparison with vaccine strains and reference strains. Results:Since the 2009 pandemic, A(H1N1)pdm09 had become one of the predominant viruses causing seasonal influenza and been reported to co-circulate with influenza A(H3N2) and influenza B viruses in Hangzhou in the past decade. It caused 10 local influenza epidemics in the 12 consecutive seasons from 2009 to 2020. HA gene sequencing revealed complex sources and rapid variation of the local A(H1N1)pdm09 strains. The main epidemic strains often genetically drifted from the recommended northern hemisphere vaccine strains due to lineage changes. Conclusions:This study suggested that it was essential to update the recommended vaccine strains year by year. Besides, enhanced periodic monitoring of influenza A(H1N1)pdm09 strains circulating in the region was important for the prevention and control of influenza A(H1N1)pdm09 infection in the next epidemic season.
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Objective:To study the pathogenic spectrum of enterovirus (EV) in the samples of child influenza-like(ILI)cases in Hangzhou city .Methods:In 2019, 1 060 throat swab specimens of ILI cases were collected for serotyping of influenza virus and EVs by real-time RT-PCR. The positive rates of influenza virus and EV in spring, summer, autumn and winter were compared by chi-square test with SPSS16.0 software. Specific primers were synthesized and used to amplify the VP1 fragments of EV. PCR products were sequenced and the results were compared with the reference sequences by using Basic Local Alignment Search Tool (BLAST) to identify the serotypes of isolated EV. The clinical diagnoses of EV positive cases were classified and analyzed.Results:A total of 1 060 specimens were collected and 283(26.70%) were positive for influenza virus, 75(7.08%) were positive for EV, 3(0.28%)were positive for influenza virus and EV. The comparison of positive detection rate of spring, summer, autumn and winter showed that influenza virus were prevalent in winter and spring. EV were mostly popular in the summer months. VP1 sequences of 51 EV were successfully amplified and BLAST analysis revealed that these strains belonged to 10 serotypes, including five serotypes of EV-A species, four serotypes of EV-B species and one serotype of EV-D. The ten serotypes of EV, including coxsackievirus (CV)A2, A4, A5, A6, A9, A10, and echovirus (ECHO)7, ECHO11, ECHO18, and EV-D68 were obtained and the percentages of positive were 16.00%, 16.00%, 5.33%, 12.00%, 5.33%, 1.33%, 1.33%, 5.33%, 4.00% and 1.33%, respectively. The phylogram of EV VP1 sequence showed that 51 EV strains in Hangzhou had different degrees of variation compared with the reference strains. Acute upper respiratory tract infection was the main clinical diagnosis in EV positive children, with 44 cases (58.67%). Acute tonsillitis was followed by 14 cases (18.67%). Followed by herpetic pharyngitis, acute bronchitis, asthmatic bronchitis, pneumonia, accounting for 12.00%, 8.00%, 1.33%, 1.33%, respectively.Conclusions:EV causing influenza-like illness in children in Hangzhou in 2019 belonged to 10 serotypes, CVA2 and CVA4 were the predominant serotypes, and the positive rate of EV detection was higher in summer.
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Objective To study the influence of edaravone on malondialdehyda(MDA)and expression of Hsp-70 and Bcl-2 in the perihematoma region in rats.Methods A total of 120 health male rats were randomly divided into false-operation group(n=20)、intracerebral hemorrhage(ICH)-therapy group(n=50)and ICH control group.Each group was further divided into 5 subgroups respectively according to 6 h、24 h、48 h、72 h and 5d after model creation.Cerebral hemorrhage model was duplicated with the method created by Fredrik.Brain water content and MDA were measured.Expression of Hsp-70 and Bcl-2 were assayed in each group with immunohistochemical method.Results Brain water content and MDA were lower in ICH-therapy group than those in control group(P